As reported (in a paper called "Terms used for children’s games", published in the 1996 Focus on the USA) by Luanne von Schneidemesser, based on results from a 1994 survey, for 296 informants ("younger people") responding to "In a game of tag, if a player wants to rest, what does he call out so that he can’t be tagged?" (DARE Question EE17),
Times was reported 20 times...times has spread as far west as Texas, Oklahoma, Colorado, and Minnesota, as well as one response in Arizona.
[Text as found in Dictionary of American Regional English Online; paywalled.]
The simple exclamation 'times!' is one of several variants. DARE supposes the sense is probably "transf[erred] from time out a brief suspension of play in var[ious] organized sports (OED2 time out...)" (op. cit.).
Of the variants time(s), times out, and times ex (rare), DARE observes that ex in the equivalent phrase king's ex
is often assumed to be an abbr[eviation] for excuse, [but] it seems more likely that it, as well as (s)cruce(s) and crosses, refers to the act of crossing the fingers, often an essentail part of claiming a truce or time out.
[From the entry for "king's ex exclam, n", DARE (paywalled).]
In addition to DARE and von Schneidemesser's more 'scientific' data collection, commenters at this site (ELU) aver the use of the exclamation 'times!', sometimes accompanied by a 'T' hand gesture, in the children's game sense of "time out" in California (undated, and 1980s) and Nova Scotia (1990s), etc.